The New Mexico Rare Arthropod Resource

Very little is known about the ecology of this taxon. However, this taxon is associated with scrub oaks, especially Turbinella Oak (Quercus turbinella) (Ferris 1980, Cary and Toliver 2023). There seems to be evidence in fact that Turbinella Oak is the sole host plant of S. p. organensis (Cary et al. 2012). However, more research is needed on the subject. The original authors write that these scrub oaks usually grow on steep talus slopes which makes finding individuals difficult. This species is found between 5400 and 7000 feet (1646 - 2134 meters)(Cary and Toliver 2023). This taxon has been observed nectaring on Antelope Horns (Asclepias asperula) a milkweed species, however, it likely nectars on other species as well (Ferris 1980). Although nectar sources are generally very limited for this taxon as its flight occurs during a very dry time of year (Cary Pers comm. 2023). Larvae of S. p. organensis hatch in March and feed through March and April before pupating generally in early May (Cary et al. 2012). This taxon then flies from mid-May to mid-June before overwintering as eggs (Cary et al. 2012). 

It has been hypothesized that this taxon exists as multiple small colonies within a single metapopulation in which there's a balance between extinction and recolonization over years (Cary et al. 2012). This is interesting as evidence suggests most years that females don't wander more than a few meters from their host plant. Likely this taxon only disperses and recolonizes in years where conditions are exceptionally good (Cary et al. 2012).

The threats for this taxon are not well understood and more research is required however, a variety of threats affect this taxon currently to an unknown degree. First off, the eastern slope of this taxon's habitat in the San Andres mountains lies within the boundaries of the White Sands Missile Range. This area is inaccessible except by special permit and even then, only in certain areas (Ferris 1980). Thus, the area is thought to be decently protected; however, military training and exercises can cause serious impacts to biodiversity and species populations (Lawrence et al. 2015). 

The western slope of this taxon’s range in the San Andres mountains is experiencing a very different threat coming from the Bureau of Land Management grazing allotments and private inholdings. Feral cattle and the invasive species they bring with them are potentially seriously disrupting the local fauna including nectar sources that this taxon relies on. In other places across the American west grazing and the invasive grasses and broadleaved plants that come with them have been disastrous for butterfly populations (Schtickzelle et al. 2007, Cushman 2009). Grazing was recently expanded in 2016 in Organ Mountain Desert Peaks National Monument (Eilperin 2017) leading to the intensification of this threat. There have already been some observed impacts of this in the Organ and San Andres Mountains with other species. A prominent one is the Organ Mountains Scaleseed (Spermolepis organensis) which is endemic to the Organ mountains and considered globally critically imperiled due to the threat of livestock ranching and the invasive species brought with it (New Mexico Rare Plant Technical Council 2017). Historically there was domestic grazing of Angora Goats (Capra aegagrus hircus) in the area and observations of known former angora goat ranches showed large numbers of acacia trees and no oaks (Cary et al. 2012). Additionally, there is grazing from the introduced African oryx (Oryx gazella) within this taxon’s range (Cary et al. 2012).

Additionally major threats to the flora and fauna of this region include drought and climate change. Way back to its description it was remarked how dry even for the American southwest this area is (Ferris 1980). This butterfly also usually is out in a very dry time of the year and so nectar sources are usually very limited for this taxon (Cary pers comm 2023). Already with so little water larger droughts and competition with cattle could easily result in major impacts to this taxon. This is especially true as this species host plant has been documented to need very wet years in order to germinate its seeds and recently with increasing drought length and severity few years have reached the threshold required for seed germination (Pase 1969, Williams et al. 2022). It has also been well documented that drought and rising temperatures are leading to declines in many butterfly species across the United States (Forister et al. 2010, 2021 Wepprich et al. 2019). Additionally, a large wildfire could potentially wipe out a large amount of the viable habitat for S.p. organensis as well as resulting in mortality of larvae and eggs this could result in sharp population declines from which it would be difficult to recover from ( Bond and Bradley 2003, Marschalek and Deutschman 2019). Habitat loss from development and resource extraction are also threats to this taxon. Habitat loss across the American west has been a major threat to many butterfly species (Forister et al. 2010, Flockhart et al. 2015, Wepprich et al. 2019). This is all compounded by how geographically isolated this taxon is in these two mountain ranges (Ferris 1980) one threat could easily spread and affect the entire population. This seemingly puts S.p. organensis at risk and efforts should be made to understand the threats potentially threatening this taxon and reduce them.

As a metapopulation, this species is thought to go through a regular balance of extinction and recolonization with populations disappearing in dry years and then recolonizing lost territory in really good wet years (Cary et al. 2012). However, there is concern that as drought severity and length increases that this species may be unable to recolonize territory it is losing and that the species EOO, AOO, and population could crash (Cary et al. 2012, Williams et al. 2022). This could also be further extenuated by host plant declines due to severe drought, nectar scarcity, and wildfire (Pase 1969, Cary et al. 2012).